The use of impact-type particle separators to remove solid material entrained in a gas is well known. Typical examples of
such particle separators are illustrated in U.S. Pat. No. 2,083,764 to Weisgerber, U.S. Pat. No. 2,163,600 to How, U.S. Pat. No. 3,759,014 to Von Dyken, II et al., U.S. Pat. No. 4,253,425 to Gamble et al., and U.S. Pat. No. 4,717,404 to Fore.
With respect to fluidized bed combustors, particle separators can be categorized as being either external or internal. External type particle separators are those located outside the furnace enclosure with typical examples being illustrated in U.S. Pat. No. 4,640,201 and 4,679,511 to Holmes et al., U.S. Pat. No. 4,672,918 to Engstrom et al., and U.S. Pat. No. 4,683,840 to Morin. Internal type particle separators are those located within the furnace enclosure and are illustrated in U.S. Pat. No. 4,532,871 and 4,589,352 to Van Gasselt et al., U.S. Pat. No. 4,699,068, 4,708,092 and 4,732,113 to Engstrom, and U.S. Pat. No. 4,730,563 to Thornblad.
These latter internal type separators either involve baffles across the entire freeboard space that would be difficult to unclog and support or they involve an internal baffle and chute arrangement which closely resembles the external type of particle separators.
It is thus an object of this invention to provide a particle separator that is located within the furnace enclosure but which does not create an obstruction in the furnace freeboard. Another object of this invention is to provide an internal-type particle separator that requires no re-configuration of the furnace enclosure or chutes for the collected particles. A further object of this invention is to increase average density of the furnace as well as solids residence time. Such increases enhance furnace heat transfer rates and improve the carbon conversion efficiency. Additionally, improved sorbent utilization occurs for greater sulfur capture without increasing external solids circulation rate. These and other objects of this invention will become obvious upon further investigation.